Security systems are normally deployed in homes and in other areas to prevent theft, damage, and injury to residents within the homes. More particularly, these systems include various alarm components or elements which are physically connected (e.g. by wire) to a central console. These elements generate an electrical signal upon the occurrence of an event such as the opening of a door or window or the presence of pressure upon a window or other portion of the house. Upon receipt of these signals, the central console typically activates a siren to “warn away” potential intruders and further communicates an alarm signal to a central monitoring station, effective to allow the central monitoring station to notify the police or other local authorities of the presence of an “alarm condition.”
Traditionally detector apparatuses, such as burglar detectors, transmit an alarm message to a central apparatus of the security system via a wired connection when the detector apparatus detects an alarm condition. When the central apparatus receives an alarm message it uses alarm means, such as a siren or a light, to raise an alarm. Also, a silent alarm may be raised, for instance by triggering a remote security company or the police. Such systems are typically installed and maintained by professional companies. Similar systems of reduced complexity are available for domestic use and can be installed and maintained by a technically skilled consumer.
The conventional home security system typically needs wiring connection to electrically connect a number of indicating lights, buzzers, emergency buttons, and common power source connection at every house end. In the case that an emergency happens to any in the common system (for example, including 8-16 house ends), the application at one emergency button will trigger all buzzers and indicating lights in the system for successfully broadcasting the emergency situation and sending out the emergency signal.
However, the construction of the common power source, relative electricity devices, and the electrical wiring network is easily damaged, and thus is apt to induce a fault triggering which will disturb all customers in the system, raise unexpected anxiety, and even cause the whole system to shut down.
In considering the electric utilities safety, the conventional wiring system is usually restricted by the existing construction. For example, difficult work such as digging or breaking the wall is always possible in constructing the wiring. Also, the geometrical characteristics in the neighborhood enhance the possibility of exposing the wiring to the atmosphere while the wiring passes across the street and in which will increase the maintenance problem as well.
With the continuing drop in cost and power requirements of electronic components and the liberalization of the use of certain RF transmission bands, cost-effective cordless system have become available which can be installed and maintained by the general public. Such a system is known from the Home Security System, 1995 of Grundig, for example. Each detector apparatus is locally powered, for instance, by a battery. The detector apparatus transmits a message via RF to the central apparatus, upon detecting an alarm condition, making the system fully cordless. Unlike wired systems, the communication is, in principle, not restrained to the principal area to be protected by the system. Typically, the communication range is 30 meters, allowing the system to cover an area with a diameter of approximately 60 meters, with the central apparatus at the center. In many domestic situations this implies that (parts of) neighboring houses or apartments are included in this communication area, whereas, in general, the area to be protected is limited to a smaller area, such as one house or one apartment. To ensure that the central apparatus only responds to alarm messages transmitted by detectors, which are intended to be guarded and, for instance, not by detectors which are part of a neighboring security system, a alarm message is only accepted if it is transmitted by a detector which is known to the central apparatus. Each apparatus has a unique communication address.
Whenever a detector apparatus transmits an alarm message, the unique address is included in the alarm message as the source address of the message. Before an alarm message is accepted from a specific detector apparatus, the detector apparatus needs to be trained to the central apparatus. During the training, first the central apparatus is brought into a learning mode, by using a key to bring the central apparatus into the installation mode and pressing a button on the central apparatus to bring the central apparatus to a learning mode. Next, an alarm is triggered on the detector apparatus, which needs to be learned. Typically, a tamper alarm is triggered. Upon receiving the resulting alarm message, the central apparatus stores the source address of the received alarm message in a memory. The user can select the memory location in which a specific detector is stored. Using buttons on the central apparatus, the user can selectively disable or enable memory locations. Alarm messages from a detector apparatus, whose memory location has been disabled, are not acted upon by the central apparatus. In this ways, zones of a house, each covered by a detector apparatus, can selectively be guarded or not guarded. It is desired that the chance is reduced of an apparatus being trained, which should not be part of the system. In order to avoid that a neighboring detector apparatus, which transmits an alarm message at the moment of the central apparatus being in the learning mode, is stored in the central apparatus, the Home Security System of Grundig requires a detector apparatus to be near the central apparatus for the detector apparatus to be accepted. Since the normal operational distance is larger, this requires the central apparatus to use different thresholds for receiving messages.
Furthermore, limiting the operational distance provides no adequate protection in certain situations of, for instance terraced houses or apartments, where typically entrances are located immediately next to one another and central apparatuses and some detector apparatuses tend to be located in the entrance halls. Moreover, this requires detector apparatuses to be near the central apparatus and not at the location/zone where the detector apparatus is intended to operate. This increases the chance of the user, mistakenly, placing a detector apparatus in a different zone than programmed on the central apparatus. Since the alarm raised by the central apparatus, in the Grundig system, is specific for a memory location (and therefore for a zone), this may have a significant impact.
Various approaches have been attempted for improving security systems. For example, U.S. Pat. No. 5,543,778 discloses a home security system that includes a plurality of alarm elements; a central console including a microprocessor in wireless communication with the alarm elements and effective to receive a signal from the alarm elements; an automobile including an alarm system in wireless communication with the central console's microprocessor and effective to activate certain alarm elements when the automobile's alarm system is in close proximity to the home security system and when the automobile is started; the microprocessor being connected to a tri-state analog to digital converter which includes a plurality of resistors whose resistance values cooperatively determined an accuracy of analog to digital conversion with respect to the received signal transmitted from the alarm elements.
An EEPROM that includes gray scale conversion is also realized. U.S. Pat. No. 5,907,279 discloses a security system, detector apparatuses (101, 102, 103) transmit an alarm message to a central apparatus 100 via RF in response to detecting an alarm condition. The message comprises a source identification uniquely identifying the transmitting apparatus. The central apparatus 100 raises an alarm if the alarm message is sent by a detector apparatus, which is part of the system. To this end, the central apparatus 100 only processes an alarm message if the source identification of the alarm message is stored in a memory means 200 of the central apparatus. For a new detector apparatus to be accepted as part of the system, the identification of the detector apparatus needs to be stored in the memory means 200 of the central apparatus. To reduce the chance of identifications of neighboring apparatuses inadvertently being stored, a detector apparatus transmits a learn-detector message in response to a learn trigger, for instance from a user. The central apparatus 100 stores the source identification of a received learn-detector message only if the central apparatus 100 is in a learning mode.
U.S. Pat. No. 6,134,303 discloses a united home security system for joining a plurality of client-sides is disclosed. The system includes a sensing circuit, a subscriber emergency handling/communication circuit, a client-side monitor/control server, a remote administrating and monitoring device, and an alarm transmitting network. Each client-side communicates with the remote administrating and monitoring device via a public telecom-network, for transmitting the state information at the client-side. In case an emergency signal is detected at any client-side, the client-side monitor/control server communicates with the remote administrating and monitoring device via the telecom-network, and then an alarm signal is generated by the alarm transmitting network.
However, the foregoing references are deficient in terms of effectiveness and/or cost-efficiency. Accordingly, it would be desirable to provide an improved security system that is effective in providing security to a property, such as a home or workplace. Further, it would be desirable to provide a security system that remedies the deficiencies or prior systems and is cost-efficient.